Minerals are inorganic elements required by the body in small amounts. They are classified as macrominerals, trace elements, and ultratrace elements based on daily requirements. Minerals serve important structural and functional roles. They are components of bones, teeth, cell membranes, and enzymes. Minerals help regulate processes like acid-base balance, fluid balance, nerve impulse transmission, and muscle contraction. Deficiencies can cause conditions like anemia, while excessive intake of some minerals can be toxic. Minerals are absorbed in the small intestine and their levels in the body are tightly controlled by hormones and homeostatic mechanisms.

1. MINERALS
Dr. Farhana Atia
Assistant Professor (Biochemistry)
Nilphamari Medical College, Nilphamari
Bangladesh

2. Minerals
Minerals are inorganic elements required in small
amounts by the body (micronutrients).
• Widely distributed in food
• Requirement vary from g/day [Na, Ca], mg/day [Fe, Zn] or
µg/day [Iodine]
• Mixed diet provide sufficient amount
• Insufficient intake produce deficiency sign (anemia,
cretinism, goiter)
• Excessive intake may be toxic

3.  Minerals are absorbed from
small intestine either
 by active transport or
 by carrier mediated diffusion
 Calcium absorption: depends
on vitamin D
 Zinc absorption: zinc binding
ligand
 Iron absorption is limited &
strictly controlled
 Functions of minerals
 Formation of bones
& teeth
 Fluid balance
 Nerve conduction
 Muscle contraction
 Signaling
 Catalysis (as enzyme
cofactors)

4. Classification of Minerals
Functions Minerals
Structural function Ca, Mg, PO
Membrane function Na, K
Prosthetic group of enzymes Co, Cu, Fe, Zn, Mo, Se
Regulatory/Role in hormone action Ca, Cr, I, Mg, Mn, Na, K
Essential but unknown function Si, Van, Ni, Sn
Have effect but essentiality is not
established
Fl, Li
Occur in foods, toxic in excess Al, As, Antimony, Bo, Br, Cd,

5. Classification of Minerals
According to daily requirements for adults

6. • Macrominerals are micronutrients required by
adults in the largest amount
• Trace elements are inorganic molecules that are
essential for life, they occur in human & animal
tissue in mg/kg amount or less.
• Ultratrace elements has been refers to element
present in tissue in mcg/kg amount or less. Dietary
requirement is also mcg/day

7. Sodium
• Distribution in body
– 50% - Bones
– 40% - ECF
– 10% -Soft tissues
• RDA : 1000-3000mg
• Dietary source-
Table salt
Salty food
Bread
Whole grains
Leafy vegetables
Fruits
Baking soda
Nuts
Egg
Milk

8. Functions of Sodium
• Regulates acid base balance
• Maintain osmotic pressure & fluid balance.
• Necessary for normal muscle irritability & cell permeability.
• Role in intestinal absorption of glucose, galactose & amino
acids.
• Involved in initiation & maintenance of heartbeat.
Deficiency: Excess:
Dehydration
Acidosis
Tissue atrophy
Edema
Hypertension

9. Banana
Orange
Pineapple
Potato
Beans
Chicken
Liver
Coconut water
Potassium
 RDA: 3-4 gm
 Dietary source:

10. Deficiency
• Acidosis
• Renal damage
• Cardiac arrest
Potassium
FUNCTIONS
 Maintains intracellular
osmotic pressure
 Regulates acid base balance
 Water balance
 Transmission of nerve impulse
 CO₂ transport

11. Fluoride
 Distribution
 Bones
 Teeth
 RDA: 3.5 - 4 mg
 Source:
 Drinking water
 Sea food

12. Functions of Fluoride
 Prevents the development of dental caries
 Forms an acid resistant protective layer on enamel
 Inhibit bacterial enzyme & decrease acid production
 Proper development of bone
 Inhibit certain ENZYME ACTIVITY
 Sodium fluoride inhibit Enolase (glycolysis)
 Fluoroacetate inhibit Aconitase (TCA cycle)

13. Clinical Conditions

14. Manganese
 Distribution:
 Liver, kidney
 RDA: 2-9 mg
 Sources
 Tea
 Cereals
 Nuts
 Leafy vegetables
 Fruits

15. Functions of Manganese
 Cofactors for several enzymes
 Required for bone formation, normal
functioning of nervous system
 Synthesis of mucopolysaccharides &
glycoproteins
 Necessary for synthesis of hemoglobin &
cholesterol

16. Copper
 RDA: 2-3 mg
 Ceruloplasmin- Cu binding protein
 Source
 Liver
 Kidney
 Meat
 Egg yolk
 Cereals
 Nuts
 Green leafy vegetables

17. Functions of Copper
 Constituent of several enzymes
 Hemoglobin synthesis
 Collagen synthesis
 Ceruloplasmin: involved in conversion of Fe⁺⁺ to
Fe⁺⁺⁺
 Melanin & PL synthesis
 Development of bone & nervous system

18. Clinical Conditions

19. Selenium
• RDA: 50- 200 mg
• Source:
– Organ meats
• Liver
• Kidney
– Sea food

20. Functions of Selenium
• Prevents hepatic necrosis, muscular dystrophy
• Maintains structural integrity of biological membrane
• Selenocysteine- considered as 21st amino acid
• Prevents lipid peroxidation & protect cells against the
free radicals
• Binds certain heavy metals & protects body
• Se containing enzyme
– Converts T₄ to T₃

21. Zinc Mainly intracellular
 RDA : 10- 15 mg
 Source
 Meat
 Fish
 Egg
 Milk
 Beans
 Nuts
 Metallothionein- Transport protein

22. Functions of Zinc
• Essential component of several enzymes (carbonic
anhydrase, superoxide dismutase)
• Antioxidant– protects the body against free radical damage
• Helps in storage & secretion of Insulin from pancreas
• Maintain normal serum Vitamin A. Synthesis of retinol
binding protein
• Wound healing, enhance cell growth & division
• Essential for reproduction
• Important for taste sensation

23. Clinical Conditions

24. Iodine
• Distribution: Thyroid gland (80%), muscle,
salivary gland, ovaries
• RDA : 100- 150 mcg
: 200 mcg (in pg)
• Source
– Sea food
– Drinking water
– Vegetables & fruits (growing on seaboard)
– Iodized salt

25. • Functions of Iodine
– Constituent of thyroid hormone: T₄ (thyroxine) & T₃
(triiodothyronine)
– Regulate cellular oxidation
– Crucial for growth & development (as TH)
• Deficiency
– Goitre
– Myxedema (adult)
– Cretinism (children)

26. Clinical conditions
Goitr
e Mixedem
a
Cretinis
m

28. IRON
• Total body iron: 3- 4 gm
• RDA
– Male : 10 mg
– Female: 18 mg
– 10% of dietary iron is absorbed (1- 2mg)
• Source: Liver
Meat
Heart
Kidney
Fish
Leafy vegetables
Pulses
Cereals
Apples
Dried fruits

29. Functions of Iron
 Constituent of several proteins/enzymes- hemoglobin,
myoglobin, cytochromes, xanthine oxidase, catalase,
peroxidase.
 Transport of O₂ & CO₂ (Hb & myoglobin)
 Necessary for electron transport chain & oxidative
phosphorylation (Cytochromes & some nonheme
protein)
 Phagocytosis & killing of bacteria by neutrophils

30. Clinical Conditions
 Iron deficiency anemia
(Hypochromic
Mycrocytic Anemia)
 Hemochromatosis
 Hemosiderosis

31. Transferrin Hemoglobin
in RBC
Myoglobin &
enzyme
Stored
(Ferritin)
3-4 mg 2500 mg 300 mg 1000 mg
Iron Distribution in 70 kg adult male
Total: 3-4 gm (In female: 100-400 mg less)
Absorption & loss: 1 mg/day (Female: 1.5-2 mg/day)

33.  Transferrin: Protein
 Free iron is extremely toxic (form free radicals), so bound to Tf
 Normally Tf is 30% saturated with iron
 Ferritin
 stores excess iron in tissues (1 gm)
 Plasma ferritin (50-200 µg/dl) proportionate to total store of
iron in body
 Hemosiderin
 Degraded from ferritin
 Detected in iron overload (hemosiderosis)

34. Absorption of dietary
iron
Iron in diet:
1. Heme: Directly absorbed
2. Nonheme:
– Fe³⁺ is reduced to Fe²⁺ (by Vit C &
gastric acid)
– Transfer to enterocyte via divalent
metal transporter1
In enterocyte
1. Stored as ferritin
2. Go to circulation by ferroprotein
– Fe²⁺ oxidized to Fe³⁺
– Transported by Tf
Proximal duodenum

35. RBC life span: 120 days
Damaged erythrocytes are phagocytosed by macrophages of RES
Hb → Heme [+ globin]→ Fe+ Biliverdin
3-4 mg
20-25mg/d
5mg/d
2500mg
1000mg

36. CALCIUM
 Most abundant mineral in the body
 Total Ca: 1- 1.5 kg
 99% Bones, teeth
 1% Outside skeletal tissue but have wide variety of
functions
 RDA
 Adult : 800 mg
 Children : 800-1200 mg
 Pg, lactation : 1500 mg

37. Source
• Milk & milk products
• Beans
• Leafy vegetables
• Fish
• Cabbage
• Egg yolk

38. Distribution of plasma Calcium (2.5 mmol/l)

39. Hormonal Regulation of Calcium
3 hormones are primarily concerned
Calcitriol/active V-D
PTH
Calcitonin (Ca lowering hormone)
Others
Glucocorticoid
GH
Estrogen
Growth factors
PO₄ regulating hormone affect Ca metabolism

40. Vitamin D & Ca Homeostasis
Condition GIT Bone Kidney
↓ [Ca] ↑ Ca
absorption
↑ mobilization Active vit D formation
↑ [Ca] ↓ Ca
absorption
[+] Calcitonin
[-] Ca mobilization
↑ excretion (calcitonin)
↓ reabsorption (PTH)
Inactive vit D formation
↓ vit D No absorption [+] Ca mobilization
(PTH)
↓ excretion (PTH)
↑ reabsorption (PTH)
↑ vit D ↑ absorption ↑↑ mobilization
↑ accumulation
↑ excretion (calcitonin)
Inactive vit D formation

41. Functions of Calcium
• Activation of enzymes
– Calmodulin (Ca binding regulatory protein) binds 4 Ca⁺⁺ →
activation of enzyme protein kinase
– Directly activate
• Pancreatic lipase
• Enzyme of coagulation pathway
• Act on muscle
– Excitation & contraction of muscle fibre by increasing action
of actin & myosin
– Decrease neuromuscular irritability

42. • Secretion of hormones
– Insulin
– PTH
– Calcitonin
– Vasopressin etc.
• Act as 2nd messenger
• Reduce vascular permeability
• Act as coagulation factor
• Help in bone & teeth formation
Functions of Calcium

43. Clinical condition
 Hypercalcemia
 Hypocalcemia
 Rickets
 Osteoporosis
Hypocalcaemic tetany
Osteoporosis